• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.898-905
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• 2005

The settlement of embankment on soft clay includes shear settlement due to shear deformation. Even though the consolidation settlement is not related to lateral displacement, but shear settlement makes the embankment unstable because it deforms ground and decreases the ground strength. In order to determine the shear deformation behaviour during embankment construction, 3 cases (1B, 2B, and 3B) of rapid undrained loading tests on soft clays were performed. Shear settlement is consist of elastic settlement, plastic settlement and viscous settlement. Elastic settlement isn't considered because the range is small, therefore the first is the range of plastic displacement, and the second is that of viscous displacement in the displacement-time curve for each loading stage. After determining that the change in the inclination of the viscous displacement range is larger than in the plastic displacement range after the ground failure occurs for the loading stage, the stability management methods were suggested considering that it is hard to divide the plastic displacement range and the viscous displacement range. The stability management method was based on the ratio of the plastic displacement range's inclination and the viscous displacement range's inclination. A stability management method based on the ratio of the total inclination for each loading stage compared to the whole inclination in the initial loading stage was also recommended.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.2
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• pp.185-191
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• 2011

Plastic gradient from geometrically necessary dislocation(GND) can affect material behavior significantly. In this research, mechanical behavior of polycrystalline solid is investigated using the finite element method incorporating plastic gradient from long range dislocation or GND effect. Plastic gradient effect is implemented in the analysis model by considering a long range strain term as well as elastic and plastic terms in the multiplicative decomposition. In the model, gradient hardness coefficient and length parameter are used to evaluate the effect of the long range strains and sensitive study is conducted for the parameters. It is confirmed that the GND amplifies hardening response of polycrystals compared with the single crystal.

• Archives of Plastic Surgery
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• v.41 no.4
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• pp.330-336
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• 2014

Background For patients with full thickness skin defects, autologous Split-thickness skin grafts (STSG) are generally regarded as the mainstay of treatment. However, skin grafts have some limitations, including undesirable outcomes resulting from scars, poor elasticity, and limitations in joint movement due to contractures. In this study, we present outcomes of Matriderm grafts used for various skin tissue defects whether it improves on these drawbacks. Methods From January 2010 to March 2012, a retrospective review of patients who had undergone autologous STSG with Matriderm was performed. We assessed graft survival to evaluate the effectiveness of Matriderm. We also evaluated skin quality using a Cutometer, Corneometer, Tewameter, or Mexameter, approximately 12 months after surgery. Results A total of 31 patients underwent STSG with Matriderm during the study period. The success rate of skin grafting was 96.7%. The elasticity value of the portion on which Matriderm was applied was 0.765 (range, 0.635-0.800), the value of the trans-epidermal water loss (TEWL) was 10.0 (range, 8.15-11.00)$g/hr/m^2$, and the humidification value was 24.0 (range, 15.5-30.0). The levels of erythema and melanin were 352.0 arbitrary unit (AU) (range, 299.25-402.75 AU) and 211.0 AU (range, 158.25-297.00 AU), respectively. When comparing the values of elasticity and TEWL of the skin treated with Matriderm to the values of the surrounding skin, there was no statistically significant difference between the groups. Conclusions The results of this study demonstrate that a dermal substitute (Matriderm) with STSG was adopted stably and with minimal complications. Furthermore, comparing Matriderm grafted skin to normal skin using Cutometer, Matriderm proved valuable in restoring skin elasticity and the skin barrier.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.681-687
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• 2002

The cumulative, shrinkage plastic strains and their distributions in the weld joint after completion of the welding process determine welding-induced distortion. Although the weldment undergoes many complex physical and metallurgical changes during welding, only the material plastic temperature range and its cooling history below this temperature range influence the [mal state of the cumulative shrinkage plastic strains. In addition, for structural welds, these plastic strains are uniform, except in the arc start and stop regions, along the weld. Therefore, the plastic strain-based "inherent shrinkage model" is effective and accurate to describe welding-induced distortion. This paper presents the theoretical background and numerical verification of this root cause.

• Journal of the Korean Society of Physical Medicine
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• v.13 no.1
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• pp.99-105
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• 2018

PURPOSE: The aim of this study was to evaluate the concurrent validity and clinical usefulness of the universal plastic goniometer to measure the range of motion of the internal and external rotation of the hip joint using the three dimensional motion analysis which can analyze the joints and segment movements in the most objective and quantitative method. METHODS: Clinical and kinematic data were collected from thirty individuals using a universal plastic goniometer and a ten camera motion analysis system. Passive hip rotation range was obtained three trials for left and right hip joints using two measure methods simultaneously. RESULTS: There were significant differences between all matching measures of the two measures of internal and external rotation of the hip joint (p<.05). The relationship between the two tests for all measurements of the internal and external rotation of the hip was statistically significant with correlation coefficient form r=.87 to .96. (p<.01). CONCLUSION: Clinical measurement of the internal and external rotation of the hip using a universal plastic goniometer is effective to assess the hip condition. However, application of universal plastic goniometer requires careful attention in more accurate evaluation and research verification of the internal and external rotation of hip joint.

• Archives of Plastic Surgery
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• v.50 no.4
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• pp.370-376
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• 2023

Background The posterior ledge (PL) is a vital structure that supports the implant posteriorly during orbital floor reconstruction. This study describes a technique for mapping the PL in relation to the infraorbital margin (IM) in patients with orbital floor blowout fractures. This study establishes the location of the optic foramen in relation to the PL. Methods Facial computed tomography (FCT) scans of 67 consecutive patients with isolated orbital floor blowout fractures were analyzed using Osirix. Planes of reference for orbital fractures, a standardized technique for performing measurements on FCT, was used. Viewed coronally, the orbit was divided into seven equal sagittal slices (L1 laterally to L7 medially) with reference to the midorbital plane. The distances of PL from IM and location of optic foramen were determined. Results The greatest distance to PL is found at L5 (median: 30.1 mm, range: 13.5-37.1 mm). The median and ranges for each slice are as follows: L1 (median: 0.0 mm, range: 0.0-19.9 mm), L2 (median: 0.0 mm, range: 0.0-21.5 mm), L3 (median: 15.8 mm, range: 0.0-31.7 mm), L4 (median: 26.1 mm, range: 0.0-34.0 mm), L5 (median: 30.1 mm, range: 13.5-37.1 mm), L6 (median: 29.0 mm, range: 0.0-36.3 mm), L7 (median: 20.8 mm, range: 0.0-39.2 mm). The median distance of the optic foramen from IM is 43.7 mm (range: 37.0- 49.1) at L7.

• Archives of Plastic Surgery
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• v.48 no.3
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• pp.261-268
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• 2021

Background Various methods have been described to close large meningomyelocele defects, but no technique has been proven superior to others. This study presents cases of meningomyelocele defect closure with a keystone-design perforator island flap. Methods A retrospective study was performed on 14 patients with meningomyelocele defects closed using various types of keystone flaps. Results The median age of the patients at surgery was 10.5 days (range, 1-369 days) and the average defect size was 22.5 cm² (range, 7.1-55.0 cm²). The average operative time for defect closure was 89.6 minutes (range, 45-120 minutes). Type IV bilateral keystone flaps were used for four defects, type IV unilateral flaps for six defects, type IIA flaps for two defects, and type III flaps for two defects. Conclusions All the defects healed completely with no major complications. The keystone-design perforator island flap is a reliable, easy, and fast technique to close large meningomyelocele defects.

• Archives of Reconstructive Microsurgery
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• v.20 no.1
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• pp.18-25
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• 2011

Purpose: In the process of replantation of the amputated fingertips, the primary concern was given to survival of the amputees, while the functional aspect of digits after the surgery has been easily neglected. Although an internal fixation with a K-wire is often a part of replantation of the amputated fingertips, little consideration had been given to the study of relationship between distal interphalangeal joint fixation and post operative range of motion. A comparative study in relation to post operative range of motion was done on two different groups, one group with K-wire insertion and the other group without a K-wire insertion at the distal interphalangeal joint. Materials and Methods: The study was done on the cases of a single digit amputation conducted at our institute (the age in the range of 10 to 60) in about four-year of time span from March of 2005 to March of 2009. The cases with a thumb replantation, osteomyelitis or articular surface injury have been excluded from this study. The cases of both head and shaft fracture, except the insertion site of tendon, of distal phalanx of internal fixation with a single K-wire were reviewed for this study. A group of 24 cases without distal interphalangeal joint fixation in comparison to a group of 22 cases with distal interphalangeal joint fixation was reviewed to assess the postoperative range of motion at distal interphalangeal joint on the 6th week after the surgery. And, on the 30th month after the surgery, a group of 10 cases without distal interphalangeal joint fixation in comparison to a group of 10 cases with joint fixation was reviewed. A K-wire was removed in about 5 weeks after the fracture was reunited under the radiographic image, immediately followed by a physical therapy. Result: The active range of motion for a group without interphalangeal joint fixation was measured $49.0^{\circ}$ on average, while $28.6^{\circ}$ was measured for a group with interphalengeal fixation on the 6th week after the surgery. On the 30th month after the surgery, the active range of motion was measured $52.0^{\circ}$ and $55.0^{\circ}$ on average for a group without and with interphalangeal fixation respectively. Conclusion: In the process of replantation of the amputated fingertips, short-term(on the 6th week) improvement of postoperative active motion of range can be expected in the cases without distal interphalangeal fixation in comparison to the cases of interphalangeal joint fixation with a K-wire. However, there seems to be no difference on motion of range in a long-term (on the 30th month) follow up period.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.183-190
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• 2000

Effective range of Hydraulic Hammer Compaction was studied by numerical analysis instead of empirical method. Numerical analyses were carried out with commercial FEM code, ABAQUS, and verified by comparing the numerical results with field tests of Hydraulic Hammer Compaction. Most of material properties were evaluated by data from laboratory and in-situ tests. Vertical effective range was estimated by distribution curve of plastic strain energy dissipated through soil layers under dynamic load and these results were in good agreement with field tests. Based on verification, the effects of governing properties of Hydraulic Hammer Compaction such as number of hit can be determined by numerical analyses. In addition, vertical effective range can also be determined by Menard's empirical equation using the external work at converging time of plastic strain energy in numerical analysis. This implies that the minimum energy of Hydraulic Hammer Compaction for improvement can be determined by Menard's equation.

• Journal of the Korean Institute of Gas
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• v.7 no.2 s.19
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• pp.48-53
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• 2003

This study is to look at the effect for deformation of carbon steel for high-presure pipe, on the AE signals produced by tensile test. Acoustic emission(AE) has been widely used in various fields because of its extreme sensitivity, dynamic detection ability and location of growing defects. We investigated a relationship failure mode and AE signals by tensile test, From the tensile test, we could divide into four ranges of the failure modes of elastic range, yield range, plastic range before $\sigma$u, plastic range after $\sigma$u. And failure behaviors of elastic range, yield range, plastic range before $\sigma$u, plastic range after $\sigma$u could be evaluated in tensile test by AE counts, accumulation counts and time frequency analysis. It is expected to be basic data that can protect a risk according to tensile test and bending of pipe material for pressure vessel, as a real time test of AE.